It is a common practice to combine a synchronization signal or pulse with one or more component R-G-B video signals. Generally, the synchronization pulse is provided either within the green video signal alone (i.e. sync on green) or within all three video signals (i.e. sync on R-G-B). Alternatively, a synchronization pulse separate from the component R-G-B video signals may be employed.
In many video signal processing systems, however, the synchronization pulse must be removed or stripped from the incoming R-G-B video signals before the R-G-B video signals can be processed by various signal processing circuits. The synchronization pulse must then be reinserted into or combined with the appropriate R-G-B video signals after signal processing is complete. For example, it is desirable to remove the synchronization pulse prior to storing representations of the R-G-B video signals within a framestore and to restore a reconstituted synchronization pulse to the R-G-B video signals for further processing.
In view of the different types of synchronization that may be employed in various video signal applications, it would be desirable to provide a general video signal processing system that was capable of processing video signals containing all of the different types of synchronization formats. Accordingly, a general video signal processing system would require a method and apparatus for automatically detecting the presence of a synchronization pulse within one or more of the R-G-B video signals prior to signal processing and providing the synchronization pulse within the respective R-G-B video signals after signal processing was complete. The provision of such an apparatus is an object of the present invention as will be described in greater detail below.